Cartridge actuated thruster



Nov. 5, 1963 J. M. sAwYER 3,109,283

CARTRIDGE ACTUATED THRUSTER Filed June 15, 1961 4 Sheets-Sheet 1 I 5| l l 4 4 I 36 24 37 33 I FIG. 2

FIG I I as I 25 I l I INVENTOR John M. Sawyer I I 5 BY wifi ATTORNEY Nov. 5, 1963 J. M. SAWYER 3,109,283

CARTRIDGE ACTUATED THRUSTER Filed June 15, 1961 4 Sheets-Sheet 2 INVENTOR John M. Sawyer FIG.5.

FIG.4.

ATTORNEY Nov. 5, 1963 J. M. SAWYER CARTRIDGE ACTUATED THRUSTER Filed June 15, 1961 4 Sheets-Sheet 3 INVENTOR John M. Sawyer ATTORNEY Nov. 5, 1963 J. M. SAWYER CARTRIDGE ACTUATED THRUSTER 4 Sheets-Sheet 4 Filed June 15, 1961* INVENTOR John M. Sawyer BY W W ATTORNEY United States Patent 3,10%,233 CARTREGE AtITUATED L STER John M. Sawyer, Dallas, Ten, assignor to Ling-Tented- Vonght, Iii-2., Dallas, Tex, a corporation of Delaware Filed June 15, 1961, Ser. No. 117,462 3 Claims. (61. 60-261) This invention relates to cartridge actuated thruster equipment, more particularly to cartridge actuated thrusters employed for rapidly moving or raising items of equipment or components thereof from one position to another, such as might be employed in the elevating of rocket launching platforms, etc.

In the past various types of thrusters have been suggested and employed for raising and lowering platforms and items of equipment, however none of these have proved entirely satisfactory because, in some instances, the cushioning or dampening of the thrust rod has been inadequate at the end of its stroke, or because in other instances the equipment was of a complicated nature, making it expensive to produce, as well as more difilcult to operate.

It is an object of this invention to overcome these aforementioned deficiencies and to provide a novel thruster with an improved dampening action.

It is a further object of the invention to provide a thruster which may be rapidly and eificiently and simply produced.

It is a further object of the invention to provide a novel thruster which provides a dampening action at both ends of the extending and retracting stroke.

It is still another object of the invention to provide a thruster which automatically provides a return stroke action for the piston rod.

It is still another object of the invention to provide an automatic means of returning the piston to its retracted position, after being fully extended.

Further objects and advantages will become apparent as the description proceeds and when taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a side elevational view of the exterior of the cartridge thruster invention.

FIG. 2 is a fragmentary showing of the exterior of the thruster invention, in a view transversely of FIG. 1.

FIG. 3 is a cross-sectional view of the thruster invention shown in FIG. 1, and illustrating the piston rod in its retracted position, and the cartridge and breech assembly loaded and ready for firing.

FIG. 4 is a cross-sectional view similar to FIG. 3, only illustrating the thruster invention immediately after firing, with the piston rod in motion and advancing toward its extended position.

FIG. 5 is a cross-sectional view of the thruster illustrating the piston rod fully advanced or extended, at the end of the firing stroke.

FIG. 6 is an enlarged fragmentary cross-section view, illustrating the details of the floating piston and end piston when the piston rod reaches the position illustrated in FIG. 4.

FIG. 7 is an enlarged fragmentary cross-sectional view of the cartridge assembly.

FIG. 8 is an enlarged fragmentary cross-sectional view of the forward end of the thruster.

FIG. 9 is a cross-sectional view taken along line 99 of FIG. 8, illustrating the four meter valves in other respective locations.

FIG. 10 is a cross-sectional view taken along line 1l 10 of FIG. 8 illustrating the mounting strap and the cross-sectional configuration of the accumulator tank and piston rod and casing.

With further more detailed reference to the drawings, in FIG. 1, the thruster invention 2 is illustrated in an ele-vational view as including an elongated piston rod 21, with a mounting block '22 formed integrally to the upper end of the rod. The mounting block 22 has a centrally disposed mounting eyelet or bore '23, to facilitate the mounting or attachment of the piston rod to the structure to be raised or moved by the thruster invention.

The piston rod 21 is enclosed in an elongated cylindrical casing 24. At the lower end of the casing is a breech block assembly 25, threadably mounted to the casing along its interior 25' (FIGS. 1 and 3) and retained by means of a locking nut 26. Projecting from the lowermost end of the breech block assembly (FIG. 1) is a ick 27. A semi-cylindered accumulator tank 28 is mounted laterally adjacent the casing and fixed to the casing by means of clamping straps 29 and 30. Adjacent the lower portion of the tank is a drain valve v31, for draining fluid from the tank.

At the upper end of the tank is a single hollow pipe or conduit fitting 32, which is threadably mounted to the tank at one end in fluid communication, and mounted in fluid communication at the other end to a single shutoff valve 33.

Four hollow tube assemblies 34, 35, 36 and 3 7, in parallel spaced relation, are connected in fluid communication to the shut valve 33, the operation of the shut valve acting to either prevent or to allow fluid to pass between the tank through pipe fittings into the tube assemblies or vice versa.

At the upper end of each tube assembly are hollow, individual metering valves 38, '39, il) and 41, each in individual fluid communication with their corresponding tube assembly.

Each metering valve at its other end is mounted to the enlarged housing portion 42 of the forward end plug 4-3 of the casing. Withinthe enlarged housing portion 42 are fourindividual inverted V shaped orifices 44, one of which is shown in a cross-sectional view in FIGS. 3, 4, 5 and 8. The orifices communicate at one end with their correspondingly aligned metering valves, and communicates at the other end with the reduced annular space .5 at the forward end of the casing between the casing and the piston rod (FIGS. 1, 2 and 3).

Mounted on opposite sides of the accumulator tank 2% are relief valves 4-6 and 47' (FIG. 10).

The forward end plug &3 also provides a cylindrical sleeve bearing surface support 48 for the piston rod, and a fluid fill port d9 having a bleed port is formed in the end plug opposite the housing portion 4L2, as illustrated in FIGS. 3, 9 and 10. The fill port is capped by nut members 51 and 52 and are also in fluid communication with the reduced annular space .5.

The details of the interior construction of the thruster are best illustrated in FIG. 3, in a cross-sectional view. The lower rear end of the piston rod 21 is provided with an annular piston or collar 53, fixedly mounted to the piston and snugly fitting within the casing. A pair of beryllium copper piston rings 54 and 55 are fitted into the piston 53.

Intermediate the length of the thruster invention and within the enlarged elongated annular space 56 between the piston and casing is a floating or movable piston 57. The floating piston 57 is provided with a pair of annular D ring seals 58 and 59 which separate the forward portion 56' of the annular space 56 and the rearward portion 56" into separate fluid compartments.

Adjacent conventional floating piston are a pair of Vlier ball plungers 6t and 61, mounted on the casing 24, and a pair of opposing vents 62 and 63 are provided in the casing 24, laterally adjacent the ball plungers.

The breech block assembly 25 (FIGS. 3 and 7) includes a breech 64 with a cartridge 65 inserted therein. The cartridge 65 includes a primer or firing cap 66, a

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shell or powder casing 67 and with explosive powder 58 therein, and a paper cap or disc 69 over the forward end of the shell for holding the powder 68 therein.

Below the cartridge 65 is a breech plug 79, which is threadably mounted to the end plug by means of threads 71, to hold the cartridge in place in the breech. The breech plug 7%} is provided with an enlarged bore 72, and a reduced aperture 73, which communicates with the firing cap 66. Within the enlarged bore 72 is a slidable firing pin 74, housing an annular disc portion 75, with a rod portion 76, projecting through the reduced aperture 73, and resting lightly against the firing cap es. Also within the enlarged bore 72 and imrneditaely behind the disc of the firing pin is a soil) or firecracker 77 having wick 27 projecting through an aperture 73 in a threaded cap 79, the threaded cap being threadably removable for the insertion of squib.

The piston or collar 53 at the rear end of the piston rod and the floating ring-like piston 57 provide an annular spacing support for the piston rod, to align the piston axially of the casing. The forward portion 56' of the anular space is in fluid communication with the reduced annular space 45 at the forward end of the thruster, and the reduced annular space 45 is in fluid communication with the four orifices 44 and the fill port 49 as previously mentioned. Fluid 28 substantially fills the accumulator tank 28, the connecting fittings and metering valves and orifices and the reduced annular space, as well as the forward portion 56 of the enlarged annular space.

It is intended that the thruster invention 20 be employed for such purposes as raising or elevating rocket launching platforms rapidly and efficiently. The thruster is employed in such connection by either attaching the mounting block to the rocket platform with pins or bolts being inserted into the eyelet 23, to pivotally connect the piston rod to the platform, or by merely nesting the upper end of the mounting block in a suitably located hoilow in the undersides of the platform frame.

The operation of the cartridge actuated thruster is substantially as follows: The piston rod 21 is retracted fully into the casing and the breech plug 79 is threadably removed and the cartridge 65 is inserted into the breech. The threaded cap 79 of the breech plug is removed and a squip 77 is inserted into the enlarged bore 72 immediately behind the disc 75 of the firing pin 74, the wick 27 of the squib is threaded through the aperture 78 of the threaded cap and the cap is then threaded back into the breech plug. Thereupon, the breech plug 70 is threaded into the breech, and the thruster is now ready for firing as illustrated in FIG. 3.

The firing pin rests lightly against the primer, and to fire the thruster it is only necessary to light the wick 27.

The lighting of the wick 27 explodes the squib which explosively forces the firing pin toward the primer with the rod portion 76 of the firing pin striking the primer sharply. This explodes the primer and the explosion of the primer explodes the powder 68 in the cartridge 65.

The exploding gases created by exploding powder forces the piston rod rapidly outward and upward in the manner illustrated in FIG. 4.

When the piston rod has moved substantially half the distance or length of the casing the piston 53 reaches the floating piston 57 and forces the floating piston to move and accompany the piston 53 toward the forward end of the casing.

During the first half of the piston rod stroke until the piston rods piston 53 reaches the floating piston '7 the rod moves freely and rapidly substantially unha-mpered by any major restraining force, with air being in the rearward portion compressed and urging the floating piston lightly forward, so that the air may be released through the air vents 6'2 and 63.

When the piston rod reaches the floating piston, and the piston 53 engages the floating piston, the rod continues outward forcing the floating piston toward the forward end of the casing, and this action compresses the fluid 28' in the forward annular space 56'. Since the shut-'oif valve 33 is open, the fluid may travel from the forward annular space 56 through the orifices 44, the metering valves 33-41, the pipe fittings 3%37, and shut-off valve, and conduit 32, into the accumulator tank 28.

The compression and forcing of the fluid into the accumulator tank tends to dampen or retard the thrust of the piston rod, particularly toward the end of the stroke, however, the explosive force of the cartridge is sufiicienb to maintain the momentum of the piston rod, even under the load or weight of the rocket platform, and for compressive force of the fluid, until the piston rod reaches the end of its stroke, or is fully extended as illustrated in PEG. 5.

When the piston rod reaches the end of the stroke the floating piston abuts the inner flange 43' of the container plug, bringing the piston to a stop, however the compressive force tends to cushion the stopping of the piston rod.

When the thruster has been actuated to raise a rocket launching platform, and the mounting block is pivotally connected to the plat-form, the platform may be provided with a latch, which engages when the platform has been raised, and holds the platform in its raised position, until the latch is released, after the firing of the rocket is over.

Since the fluid in 28' is under compression, when the latch is released, the fluid compression will provide a return momentum force for the piston rod, forcing or urging 1e piston back to its retracted position.

As the piston rod slides back to its retracted position, the fluid will force the floating piston to accompany the piston or collar on the piston rod, until the floating piston reaches the ball plungers, at the middle of the casing, the ball plungers being spring loaded will engage notches in the floating piston as the floating piston passes over, and bring in FIG. 3. The piston rod however is free to continue its retracting until its lower end comes to rest against or adjacent the lower end of the casing, whereuponthe piston has now been returned to its position illustrated in FIG. 3. i

A temporary vacuum is created in the lower annular" space 56" as the piston 53 continues back to the middle of the casing toward the lower end. This vacuum conthiues until sufficient air can be drawn in through the This temporary vacuvents 62 and 63 to fill the space. um tends to cushion the piston at the end of its retracting stroke, and reduce the speed of the piston when it comes to rest adjacent the breech.

Thus it may be seen that a novel highly eflicient cartridge actuated thruster is provided, adaptable for a wide variety of purposes or uses, and enabling a rapid thrust, with dampening action tothe piston rod when it reaches its fully extended position (FIG. 5) or returns to its fully retracted position (FIG. 3) with the compression fluid as an automatic means of momentum or force to assist in the return stroke. It will be obvious that the invention provides numerous other features and advantages in addition to those spe-.

cifically described, and accordingly it is not intended that the invention be limited by that which is specifically disclosed in the drawings and described in the specification, but only as set forth in the accompanying claims.

What is claimed: 1. A cartridge actuated thruster comprising an elongated cylindrical casing, a hollow elongated piston rod slidably mounted longitudinally within said casing with an annular space therebetween, mounting means at one end of said piston rod, said mounting means projecting from one end of said casing, a cartridge mounted at the other end of said casing, a tank mounted to said casing, annular support for said piston at each end thereof, floating pisthe floating piston to a halt at its position shown prevent an abrupt stopping of ton ring means within said annular space intermediate the ends of said casing, said piston ring surrounding said piston rod, fluid within said annular space between said piston ring and the one end of the casing, and means at the one end of the casing providing fluid communication between said annular space and said fluid tank.

2. A cartridge actuated thruster comprising an elongated casing, a hollow elongated piston slidably mounted longitudinally within said casing with an annular space between said piston and casing, one end of said piston projecting from one end of said casing, the other end of said hollow piston being open, said other end of said piston extending into said hollow casing and in open communication with said casing therein, a cartridge mounted to the other end of the casing adjacent the other end of the piston, a floating piston ring within said annular space, and disposed intermediate the ends of the casing, a tank mounted to said casing, fluid within annular space between the one end of the casing and the floating piston ring, means at the one end of the casing providing fluid communication between the tank and the annular space, whereby upon firing the cartridge the explosive force will thrust the piston outwardly from said other end of the casing until the other end of the piston engages the floating piston, forcing the floating piston ring toward the one end of the casing with the forcing movement of the piston ring compressing fluid in the annular space, and dampening the thrust movement of the piston.

3. A cartridge actuated thruster comprising an elongated cylindrical casing, a hollow elongated piston rod slidably mounted within said elongated casing, said piston rod being of reduced size with respect to said casing with an annular space thereoetween, mounting means at the outer end of said piston rod, said piston rod having its inner end open in full communication with said hollow casing along its interior, floating piston ring means within said annular space intermediate the length of said casing, said piston ring mean-s surrounding said piston rod, fluid within said annular space between said piston ring means and the outer end of said casing, a fluid tank mounted to the exterior of said casing, a plurality ort fluid lines connected at their one ends with said fluid tank and connected at their other ends with said casing and communicating with said annular space, and valve means to regulate the flow of fluid from the annular space to said fluid tank via said fluid lines.

References (Jilted in the file of this patent UNITED STATES PATENTS 

1. A CARTRIDGE ACTUATED THRUSTER COMPRISING AN ELONGATED CYLINDRICAL CASING, A HOLLOW ELONGATED PISTON ROD SLIDABLY MOUNTED LONGITUDINALLY WITHIN SAID CASING WITH AN ANNULAR SPACE THEREBETWEEN, MOUNTING MEANS AT ONE END OF SAID PISTON ROD, SAID MOUNTING MEANS PROJECTING FROM ONE END OF SAID CASING, A CARTRIDGE MOUNTED AT THE OTHER END OF SAID CASING, A TANK MOUNTED TO SAID CASING, ANNULAR SUPPORT FOR SAID PISTON AT EACH END THEREOF, FLOATING PISTON RING MEANS WITHIN SAID ANNULAR SPACE INTERMEDIATE THE ENDS OF SAID CASING, SAID PISTON RING SURROUNDING SAID PISTON ROD, FLUID WITHIN SAID ANNULAR SPACE BETWEEN SAID PISTON RING AND THE ONE END OF THE CASING, AND MEANS AT THE ONE END OF THE CASING PROVIDING FLUID COMMUNICATION BETWEEN SAID ANNULAR SPACE AND SAID FLUID TANK. 